Nope, it applies to all mollies... I don't usually trust chain stores and more often than not their info is wrong. While sometimes they may be right, it's always good to go online and get a second opinion.

You can still create a full tank! If I were you, I'd re-home all 3 mollies and instead come up with a new stocking plan. There's lots of nano fish available out there, and whereas they are harder to come by, they are just as exciting.

Here's a link with a bunch of fish that would work great in your tank:

I'd go with a small shoal of one of the types of cories on there (maybe 4 or 5) and then a school of one of the types of rasboras (maybe 5 or 6).

Or if you wanted, you could do a betta and then add a school of any of those listed on the page (5 or 6 in a school), or even neon tetras, which are super common and much easier to come by than some of those species.

Bring the mollies back to the pet store. The bare minimum for them is 20 gallons. 10 is way too small. I've heard stories of mollies becoming frighteningly aggressive in 10 gallons. A good alternate is platies. They look a lot like mollies, are also livebearers, and can live fine in a 10 gallon. If you get 2-3 platies, you'd be fully stocked.

Edit: Sorry, I didn't realize you were already told this. I should've read the entire thread. Platies would still be a good option.

The fish in the second picture looks like a platy to me. Anyone else? An is this petsmart a big chain sorrow like petsmart or petco? I almost never do my shopping there because they are there for 1 purpose- to make money. Whereas local fish stores that are locally owned and single shop, they generally care more about the tanks, give sound advice, have better stock and much much more variety, and also Better employes. I'd also take all of the mollies back. IMO you are overstocked already. If you want a full tank I think 4 small Cory's and 6 small schoolers is the way to o